It has been a long time coming, but the first Boeing 787
Dreamliner has rolled off the assembly line. Charles Conklin -- an avid
aviation enthusiast -- managed to snap some pictures of a fully assembled
Dreamliner sans paint.

According to Flightblogger,
the official roll-out ceremony for the Dreamliner is on July 8 with the first
delivered scheduled to take place in May of next year. The production run of
aircraft is completely booked until 2013 at the earliest.

The Dreamliner is the next generation of airliners for
Boeing and makes use of composite materials in 50 percent of its body and
wings. The use of composite materials has helped Boeing keep the weight
down which allows the Dreamliner to be 20 percent more fuel efficient than its
closest rivals. Top speed for the aircraft is Mach 0.85.

Business travelers will appreciate the integrated networking
capabilities on the Dreamliner. Boeing had initially planned to equip its
Dreamliner with wireless networking, but instead decided on a wired networking
to save 150 pounds per plane.

Please explain this to me. Would the use of wireless require some sort of shielding around the entire passenger cabin or something? I don't understand how thin air weighs more than hundreds of feet of Cat5e.

There are alot of factors at work. One of the factors is shielding for other systems.

Another is that every structure on the aircraft needs to be attached to the aircraft such that the structure is good for 9g loading. A heavy wireless access point (or more likely several heavy wireless access points) may require more and more structure to maintain flight capability which would not be required for a wire installation that may not require any additional structure

I am sure there are many more factors that one only really discovers attempting to create a wireless network that would be of same quality as wired.

I doubt that the entire structure needs to be able to survive 9g loading. Do you have a source for your information? I just can't imagine this aircraft having a flight envelope any larger that 2.5g, and factor of safety in aircraft design is usually not larger than about 1.2 due to weight constraints.

The max design load is nowhere near 9G. That 9G figure is for fighter jets. I believe the typical airliner is designed with a max load factor of 4-ish. Add to this the structure must handle 1.5x this load factor without failure (but with permanent deformation).

Federal Aviation Regulations. In specific FAR Chapter 25 subpart C - 25.591 of which the following is a brief quotation.

"(3) The occupant experiences the following ultimate inertia forces acting separately relative to the surrounding structure:

(i) Upward, 3.0g

(ii) Forward, 9.0g

(iii) Sideward, 3.0g on the airframe; and 4.0g on the seats and their attachments.

(iv) Downward, 6.0g

(v) Rearward, 1.5g

(c) For equipment, cargo in the passenger compartments and any other large masses, the following apply:

(1) Except as provided in paragraph (c)(2) of this section, these items must be positioned so that if they break loose they will be unlikely to:

(i) Cause direct injury to occupants;

(ii) Penetrate fuel tanks or lines or cause fire or explosion hazard by damage to adjacent systems; or

(iii) Nullify any of the escape facilities provided for use after an emergency landing."

I read this as saying any structure which has the possiblity to fall within the passenger cabin and hurt passengers must stay attached at a 9g landing situation and other emergency situation such as a 3g sideways evasive action.

I just assumed that some/all of the wirless equipment fell under this category

"(2) When such positioning is not practical (e.g. fuselage mounted engines or auxiliary power units) each such item of mass shall be restrained under all loads up to those specified in paragraph (b)(3) of this section. The local attachments for these items should be designed to withstand 1.33 times the specified loads if these items are subject to severe wear and tear through frequent removal (e.g. quick change interior items)."

I had an aircraft design course this spring, my group designed a military transport aircraft. We didn't take the 9g forward inertia forces into account too much, but it was just a preliminary design course.

Military requirements may be totally different. Due to significantly lower cycles, higher inspection intervals, not caring if a few grunts here or there get smacked on the head...

The FARs are neat and show that in many cases the Margin of Safety for civilian aircraft is significantly larger than 1.2 due to survivability requirements (check out the ditching condition. I have a hard time believing the A380 or B747 are good for those...)

I would venture to guess that it is because most of the wiring for a wired network is already in place. Perhaps the cable that also carries data to the LCD screens and audio to each seat can also handle networking duties? If this were the case, the extra wait would only be from adding the additional ports, etc. to each seat.

Which airline doesn't paint their planes (they only use clear coat) to save on the weight of the plane. I can't remember the amount of fuel saved per 1000 miles of flight but it was astounding. Paint weighs alot. Also one flight line cut back the number of olives it put on it's salad to reduce costs on both food and weight and they reported a massive annual savings.

I know, no sources, but someone here probably has them on hand, or has the time to look them up.

Look, its because the fucking wireless will be obsolete every 2-4 years, while cat 5 wont go until the end of the lifetime for the plane.Jesus, I thought that was pretty obvious. You have to just look at it from a money perspective. If you were going to own one, would you want ot have to pay expensive technicians to install expensive equipment every 4 years throughout the entire 30 year lifetime of the plane, or simply install the cat5 hookups once, and then never have to replace the damn things?

Years ago, in another life it seems, I worked for Boeing Electronics building wiring for military and commercial aircraft. The commercial classes we built were 737,747,757,767 and 777. When I started, I started on the 747 team and was told the 747 had over 150 miles of wiring inside of it.

If you've ever seen a large aircraft, you can believe this number. Each ounce counts on such a massive design.

Additionally, you have to remember that most commercial avionics have double and triple redundancy. Why would the wireless network be any different?

So, something you were originally saying was 150 lbs now becomes 300 or 450 lbs to maintain redundancy.

I seriously doubt they would bother with networking redundancy so overpaid execs are assured of 24/7 share prices :) I didn't design the 787 but I would bet my left foot the network infrastructure for passengers bears little resemblance to that of the flight systems!

One other thing about wireless, it seems to me it would really begin to chug with a full planeload of people all on laptops, PSPs, wap phones and PDAs.... Give me gigabit ethernet ANY day over wireless.

Question: anyone know what sort of internet access speed the 787 setup might offer or how it's delivered to the plane?

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